A vehicle transmission allows a gear ratio between an engine and drive wheels of the vehicle to change as the vehicle speeds up and slows down. The transmission may be manual, automatic or an automatic manual. A manual transmission permits a vehicle operator to manually control the changing of the gear ratios available to the transmission. An automatic transmission changes the gear ratio automatically. An automatic manual transmission, however, gives the vehicle operator some limited control over the change of the gear ratio and also controls the changing of the gear ratio in the event the vehicle operator chooses not to change the gear ratio. 
For an automatic and an automatic manual transmission, the rate of the shift between one gear ratio to another gear ratio is constant. A constant shift rate, however may be undesirable. Indeed, the need to shift may vary from driving situation to driving situation. For example, a vehicle in cruise control mode requires very little shifting between gears. On the other hand, a vehicle climbing up a hill requires fast and responsive shifting. Yet, in existing automatic transmissions and automatic manual transmissions the rate of shifting is the same for both situations. For a manual transmission, the rate of shifting is dictated by the vehicle operator. However, for automatic manual and automatic transmission, the rate of shifting is typically preset.  
A need therefore exists for a motor vehicle that provides the convenience of an automatic transmission and permits the alteration of the shift rate to accommodate for a particular driving circumstance. 